FR3074347A1 - ELECTRONIC DRONES TELE-CONTROL SYSTEM, ASSOCIATED COMPUTER PROGRAM PROCESS - Google Patents

Abstract

An electronic drone piloting system (3) (2), adapted to detect a risk of crossing the authorized flight limit according to data of definition of the authorized flight limit (s) and the geographical location of the drone or a remote control command received and for - determining, according to said control command and an extrapolation in time of a command according to this command, a limit crossing situation, and triggering an alarm according to said determination; or - determine another pilot control for the drone to prevent the crossing of the flight limit; or - block the transmission to the drone of the remote control command received to prevent the flight zone boundary crossing.

Description

Electronic drone remote control system, method and associated computer program

The present invention is in the field of remotely piloted or controlled aircraft, also called drones or UAV (for “Unmanned Aircraft Vehicle” in English) or RPA (for “Remotely Piloted Aircraft” in English).

Drones can be controlled by direct instructions on the engines and control surfaces, or by “vector” type orders (heading or route + altitude or slope), or by a complex trajectory instruction, typically a trajectory instruction composed of points GPS connected by straight segments or arcs of a circle. Part of the flight can take place out of the sight of the telepilot, who will follow him on a ground piloting station comprising an electronic system for the remote piloting of a drone.

The invention relates to such an electronic drone remote control system, comprising:

- a first telecommunication interface for establishing a telecommunication link with a drone;

a second interface for receiving drone remote control commands;

- a first database comprising data for defining the authorized flight area limit (s);

a processing unit adapted to transmit to the drone, via said first interface, remote control commands for the drone received via the second interface and adapted to receive, via the first interface, information on the current situation of the drone from the drone indicating at least its geographical position.

The flight takes place under the responsibility of the telepilot who must ensure compliance with the regulations and the safety of the persons and property overflown.

In particular, he must take care to always respect the authorized flight zones and not to enter prohibited zones. The boundaries of prohibited areas may include height coordinates and / or horizontal coordinates not to be crossed.

It is known, in order to contribute to respecting authorized and prohibited flight zones, to add to the drone an on-board virtual guarding device (in English "geocaging module" or "geofencing module") adapted to trigger the fall of the drone in the event of exceeding authorized limits. This type of independent device is particularly useful for countering faults in the on-board electronics of the navigation / guidance / flight control system, or even steering locks, faults which make the drone non-steerable and prevent the telepilot from correcting even if it has detected the fault.

However, even when a drone is equipped with such an additional virtual guarding device, the detection by the latter of an authorized limit crossing is damaging because it is accompanied by the triggering of the drone's fall and therefore of the loss probable of the drone and this even if it is a simple command or programming error by the remote pilot, or a correction reaction too late, while the whole system works well elsewhere.

There is thus a need to contribute to the respect by a drone of the limits of authorized flight zones.

To this end, according to a first aspect, the invention proposes an electronic remote control system for a drone of the aforementioned type, characterized in that the processing unit is adapted to detect a risk of crossing the flight zone limit. authorized as a function of authorized flight area limit (s) definition data extracted from the first database and from at least one first element among current situation information received and a first remote control command received via the second interface and for, following said detection, performing at least one first operation from a set of operations comprising:

the determination, as a function of said first control command and of an extrapolation over time of a control in accordance with said first command, of a situation of crossing of limit, and the triggering of an alarm as a function of said determination;

- the determination of a second remote control command intended for the drone to prevent the crossing of the flight zone limit;

- the blocking of the transmission to the drone of the first remote control command received via the second interface to prevent the crossing of the flight zone limit.

The invention thus makes it possible to automatically secure and correct the flight of a drone relative to the prohibited and / or authorized flight areas. An electronic remote control system for a drone thus makes it possible to implement preventive virtual guarding, without having to modify the on-board piloting unit of the drone and compatible with a virtual guarding device on board the drone if necessary.

In embodiments, the electronic remote control system of a drone according to the invention further comprises one or more of the following characteristics:

- the processing unit is adapted to automatically transmit the second command to the drone;

the processing unit is adapted to select a mode from among several operating modes, the determination of the second remote control command comprising, according to the selected mode, at least the determination of one of the elements from the set of elements comprising the geographical coordinates of a future drone crossing point, an operating instruction for engines and / or the rudder surfaces of the drone and a pair comprising a first heading or course term and a second altitude or slope term, said element being selected from the set of elements according to the selected mode;

the processing unit is adapted to extract information on the current situation of the drone from the drone, a first geographic location of the drone originating from a first drone location device and a second geographic location of the drone originating from a second device for locating a virtual guarding tool on board the drone, for comparing the first and second geographic locations and for detecting a difference greater than a determined threshold between said compared geographic locations;

- the electronic drone remote control system comprises a second terrain and / or obstacle database and the processing unit is adapted to update an emergency landing location of the drone to be adopted by the drone on detection of a break in the telecommunications link between the system and the drone as a function of terrain data and / or obstacles of the second base, of data for defining the authorized flight zone limit (s) of the first base, of the geographic location of the drone indicated by current situation information and of a fixed maximum deviation, in time or distance, from the location of the emergency landing, the processing unit being adapted to transmit to the drone via the first telecommunications interface the updated emergency landing location.

According to a second aspect, the present invention proposes a method for remote piloting of drones implemented in an electronic system for remote piloting of drones, comprising the following steps:

- establishment of a telecommunications link with a drone;

- reception of remote control commands from the drone;

- reception, via the telecommunications link, of current situation information of the drone from the drone indicating at least its geographical location, the process being characterized in that it comprises the steps of:

- detection of a risk of crossing the authorized flight zone limit as a function of authorized flight zone limit (s) definition data extracted from a first database comprising limit (s) definition data authorized flight zone and at least a first element among current situation information received and a first remote control command received intended to be transmitted to the drone by the remote control system; and

- following said detection, carrying out at least a first operation among a set of operations comprising:

the determination, as a function of said first control command and of an extrapolation over time of control in accordance with said first command, of a situation of crossing of limit, and the triggering of an alarm as a function of said determination;

o the determination of a second remote control command intended for the drone to prevent the crossing of the flight zone limit;

o blocking the transmission to the drone of the first remote control command received via the second interface to prevent crossing of the flight zone limit.

According to a third aspect, the present invention provides a computer program comprising software instructions which, when executed by a computer, implement a remote control method of a drone as defined above.

These characteristics and advantages of the invention will appear on reading the description which follows, given solely by way of example, and made with reference to the accompanying drawings, in which:

- Figure 1 shows a view of a remote control platform in one embodiment of the invention;

Figure 2 is a view of a drone trajectory in one embodiment of the invention;

- Figure 3 is a flow diagram of steps implemented in one embodiment of the invention.

FIG. 1 represents a platform 1 for remote control of drones comprising a drone 2 and an electronic system for remote control of a drone 3 in one embodiment, which is for example located within a station at RPS ground (in English "Remote Pilot Station").

The drone 2 and the electronic remote control system of a drone 3 are able to communicate with each other via a wireless telecommunication link 4, for example in the present case, a two-way radio frequency link. A communication protocol allowing the exchange of control and command information, often called C2 information, for example the open standard MAVLINK is used on this link.

The drone 2 comprises a wireless telecommunication interface 20, a control block 21 and a geolocation block 22. It also comprises, for example, an optional geocaging device 23.

Of course, the drone 2 also comprises the other usual elements of a drone, not shown in FIG. 1: in particular actuators, control surfaces and motors allowing the drone to move in flight.

The drone 2 can also include one or more cameras, etc.

The wireless telecommunication interface 20 is suitable for implementing the wireless telecommunication link 4 with the system 3 and exchanging data on this link 4 with the electronic remote control system 3. It comprises for example a transmitter / radio frequency receiver and a radio frequency antenna.

The control unit 21 is adapted to control the engines and control surfaces by control orders which it supplies to them on the basis of instructions previously recorded or received by the telecommunication link 4.

The control unit 21 controls the motors and control surfaces according to a setpoint mode which is:

- either a setpoint mode per flight plan (mode 1), based on a list of geographic coordinates (longitude, latitude, altitude) of flight points connected by straight segments or arcs of a circle; such a flight plan is typically recorded by the control unit 21 prior to the flight of the drone, then it is updated by modifications to the flight plan transmitted from the electronic remote control system of a drone 3 via the link telecommunications 4;

- or a direct setpoint mode (mode 2), based on setpoints directly intended for engines and control surfaces (eg pitching / nose-up, right / left tilt, in English "Pitch & Roll orders") transmitted regularly to the control unit 21 from the electronic remote control system of a drone 3 via the telecommunications link 4 and such that the instructions recently received from the system 3 are applied until new instructions are received;

- either a “vector” type of control mode (mode 3), on the basis of a vector comprising a heading to be followed (or a route) and an altitude (or a slope), transmitted regularly to the control unit 21 after updating, from the electronic remote control system of a drone 3 via the telecommunication link 4 and such as the course to follow (or a route) and the altitude (or a slope) recently received from the system 3 are followed until a new command vector is received.

In one embodiment, the control unit 21 is adapted to transmit regularly (for example, several times per second), via the telecommunications interface 20, to the electronic remote control system 3, the current state of the drone in terms of position, altitude, attitude, course, speed, accelerations, state of health.

In the embodiment considered, the geolocation block 22 is adapted to determine the geographic position of the drone 2. It includes a position sensor, for example of the GPS type, and also accelerometer, gyrometer, barometer, magnetometer sensors, all suitable for determining the geographical coordinates of the drone, for example in the form of latitude, longitude, altitude and other flight parameters such as attitude, heading, speed, accelerations ,. The geolocation block 22 is adapted to transmit this information regularly (for example, several times per second) to the control unit 21 which uses it for guidance and control, and possibly, via the telecommunications interface 20, to the electronic system of remote control 3, if this retransmission is not ensured by block 21.

The optional geocaging device 23 is also adapted to determine the geographic location of the drone 2, for example independently of the geolocation block 22. It includes for example its own set of sensors: position sensor, for example of GPS type, and also accelerometer, gyrometer, barometer, magnetometer sensors. It also includes a memory storing the geographical coordinates of the authorized and / or prohibited flight zones. The optional geocaging device 23 is adapted to determine, as a function of the current geographical location that it has determined for the drone and of the geographical coordinates of the authorized and / or prohibited flight areas, if the drone is outside any area of authorized theft or inside a prohibited area, and for such a case, initiate an emergency procedure to put an end to the offense, such as cutting the engine supply, blocking the control surfaces and / or triggering the exit of a parachute.

In an optional embodiment, the optional geocaging device 23 is also suitable for, via the telecommunications interface 20, regularly transmitting (for example, several times per minute) to the electronic remote control system 3 the last determined parameters defining the current situation of the drone.

The electronic remote control system of a drone 3 comprises a man-machine interface device 30, an electronic processing unit 33, a wireless telecommunication interface 34, a database 35 of the terrain and of fixed obstacles and a database 36 of authorized and / or prohibited areas.

The man-machine interface device 30 is configured to allow interaction with a remote pilot and comprises a display interface 30a, tactile or not, and an input interface 30b.

The display interface 30a is adapted to allow the remote pilot to display data, in particular images, supplied by the processing unit 33 and comprises for example a screen, touch or not, or a reality headset virtual (for a field of vision increased to 360 degrees depending on the direction of gaze of the telepilot).

The input interface 30b is adapted to collect orders from the remote pilot (for example it includes joysticks, buttons, keyboards, mouse, microphone and voice recognition tool to select fields displayed on the screen 30a ...) .

The wireless telecommunication interface 34 is adapted to implement the wireless telecommunication link 4 with the drone 2 and exchange data with the latter on this link 4. It includes for example a radiofrequency transmitter / receiver and a radiofrequency antenna.

The database 35 of the terrain and fixed obstacles defines a digital 3D elevation model of the entire extent (relief, obstacles, remarkable elements: city, river, road, ...) that the drone is likely to to fly over.

The database 36 of the authorized and / or prohibited zones includes the geographical coordinates delimiting the authorized and / or prohibited flight zones; the limits may take the form of minimum or maximum heights not to be crossed and / or of areas defined in terms of longitude and latitude.

In one embodiment, the drone 2 further comprises other sensors, for example air speed, incidence, wander, temperature, and the data captured are also regularly transmitted to the electronic remote control system 3 via the telecommunications interface. 20.

The electronic processing unit 33 comprises in the present case an electronic block of preventive geocaging 31 and an electronic block of command and ground control 32.

In the case of FIG. 1, the electronic processing unit 33 comprises for example a processor and a memory associated with the processor. The preventive geocaging block 31 and the electronic command and control block 32 are for example produced in the form of respective software executable by the processor and stored in the memory in the form of software instructions.

In a variant not shown, the preventive geocaging block 31 and the electronic command and control block 32 are each produced in the form of a programmable logic component, such as an FPGA (from the English Field Programmable Gate Array), or also in the form of a dedicated integrated circuit, such as an ASIC (from the English Applications Specifies Integrated Circuit).

In another variant not shown, the preventive geocaging block 31 and the electronic command and ground control block 32 are each produced by software operating on different computers, processors and / or screens.

The ground command and control unit 32 includes, for example, a graphical image generator adapted to synthesize one or more navigation images, for example of horizontal situation and vertical situation, of the current environment of the drone as a function of the data of the database 35 of the terrain and of the fixed obstacles and as a function at least of the data coming from the drone 2 recently received via the wireless telecommunication interface 34 and comprising the current geographical location of the drone 2 determined by the geolocation block 22 and optionally the parameters defining the current situation of the drone determined by the optional geocaging device 23.

The ground command and control unit 32 is adapted to supply these navigation images to the man-machine interface device 30 for displaying these images on the display interface 30a.

The preventive geocaging block 31 is adapted to receive, via the wireless telecommunication interface 34, the data transmitted by the drone 2 including the current geographical location of the drone 2 and other parameters (attitudes, speeds, accelerations, course, barometric height) determined by the geolocation block 22 and optionally the equivalent parameters determined by the optional geocaging device 23 ,. These data are firstly transmitted to the command and control unit 32.

On the other hand, the preventive geocaging block 31 is determined to detect whether the drone 2 has crossed or is likely to cross an authorized flight zone limit, as a function of the geographic coordinates of the database 36 of the authorized zones and / or prohibited and in function:

- at least one control instruction supplied by the remote pilot via the man-machine interface device 30,

- and / or the current geographic location of the drone 2 determined by the geolocation block 22,

- and / or parameters defining the current situation of the drone determined by the optional geocaging device 23, information relating to the wind, to the current state of the engines and control surfaces, etc.

In one embodiment, the preventive geocaging block 31 is suitable for, if a risk of crossing the authorized flight zone limit has actually been detected, trigger, via the man-machine interface device 30, an alert , visual and / or audible, intended to warn the remote pilot of the detected problem. It will be noted that this alert can be highly anticipated, in particular if it takes account of the piloting instruction provided by the telepilot and of its projection over time. It will for example be gradual as a function of the time remaining until the potential crossing: risk warning if the command was executed without modification until its end, then immediate reaction request when the crossing is predictable in a very short time (from the 'minute order or less)

In one embodiment, the preventive geocaging block 31 is adapted for, if a (risk of) crossing of the authorized flight zone limit has actually been detected, determine a flight correction correction instruction for the drone 2 to prevent the authorized flight zone limit crossing does not take place (or to return to the authorized flight zone): for example a left or right turn, leveling off etc.

The preventive geocaging block 31 is adapted to transmit, via the wireless telecommunication interface 34, to the drone 2, the determined correction instruction.

In one embodiment, the preventive geocaging block 31 is suitable for, before transmitting the correction instruction to the drone 2, proposing the correction instruction determined to the remote pilot, who can validate it or not, via the device man-machine interface 30. In such an embodiment, the preventive geocaging block 31 is adapted to transmit to the drone 2 the correction instruction determined only if the latter has been validated by the remote pilot.

In one embodiment, the preventive geocaging block 31 is adapted to compare the geographic location of the drone 2 determined by the geolocation block 22 and when it is available, the geographic location of the drone 2 determined on the basis of the parameters transmitted by the optional geocaging device 23, for detecting a deviation greater than a determined threshold between said compared geographic locations, for triggering an alert intended for the remote pilot when such a deviation greater than a determined threshold has been detected and for, optionally, determining a drone 2 piloting correction instruction intended to land the latter as soon as possible, as previously transmitted to drone 2 directly or after validation by the remote pilot.

In one embodiment, the preventive geocaging block 31 is adapted to selectively, depending on the control mode used by the piloting block 21 of the drone 2:

- in the case of a flight plan control mode (mode 1), check that the flight plan is already compatible with the authorized zones before it is recorded in the drone 2, according to the data in the base data from authorized and / or prohibited areas 36; in the case where the flight plan is not compatible, then the preventive geocaging block 31 is adapted to prevent the loading of the flight plan into the drone 2. In one embodiment, the preventive geocaging block 31 is adapted to then determine a standby instruction replacing the flight plan to be loaded (for example, if the flight is in progress, a hover or a circle remaining in the authorized area) and to transmit it to the drone 2 via the interface 34. In one embodiment, the preventive geocaging block 31 is adapted to alert the remote pilot, and optionally to determine a modification of the flight plan making it compatible that the preventive geocaging block 31 will transmit to the drone 2 upon validation by the remote pilot;

- in the case of a direct control mode (mode 2), the preventive geocaging block 31 is adapted for, as a function of the current position of the drone, and of the current orders controlling the drone 2, determining an extrapolation, ie calculating when and where drone 2 will reach a limit of the authorized flight area and for, depending on this extrapolation, possibly inform the remote pilot via ΓΙΗΜ 30. When a risk of exceeding the limits is proven (ten seconds or one ten meters or so for example), the preventive geocaging block 31 is adapted to replace the piloting orders supplied by the remote pilot via the man-machine interface device 30, by more adequate orders (turn or hover). , leveling off ...) and to transmit it to the drone 2 via the telecommunications interface 34; The triggering instant is calculated by the preventive geocaging block 31 as a function of the possible maneuver and current flight conditions, wind for example, in order to guarantee that it is not exceeded: addition to the instantaneous position of the best achievable corrective trajectory and verification of the limit in relation to this extrapolation.

- in the case of a vector control mode (mode 3), the preventive geocaging block 31 is adapted for depending on the current position of the drone, and on the current pilot vector controlling the drone 2 and / or in function of the piloting vector recently transmitted by the telepilot via the man-machine interface 30 which is to be transmitted to the drone 2, determining an extrapolation, ie calculating when and where the drone 2 will reach a limit of the authorized flight area and for , depending on this extrapolation, possibly inform the remote pilot via ΓΙΗΜ 30, calculate and propose a new more compatible vector. When the risk of exceeding the limit is very close, the preventive geocaging block 31 is, for example, adapted to transmit to the drone 2 such a new vector instruction or an instruction for placing in waiting circuit compatible with these limits from the current position. The triggering instant is calculated by the preventive geocaging block 31 as a function of the possible maneuver and current flight conditions, wind for example, in order to guarantee that it is not exceeded: addition to the instantaneous position of the best achievable corrective trajectory and verification of the limit in relation to this extrapolation.

It will be noted that these provisions also make it possible to prevent initiating a takeoff when the zone compatibility conditions are not met: initial position or non-compatible flight plan for example.

In addition, civil air navigation authorities also generally request that, in the event of a confirmed loss of the telecommunications link, often called the C2 link with the drone, it will automatically land as soon as possible at a fallback point on the ground , so as not to remain in an uncontrolled flight.

A virtual guarding device such as the optional geocaging device 23 can continue to operate even when the telecommunication link 4 for control and command is cut, guaranteeing no excursion beyond the authorized flight area, but most of the Autopilots or flight controllers aboard drones have an automatic return behavior at a given adjustable point "home" in the event of a link failure. For example, with reference to FIG. 2, the “home” point 20 has been defined for the trajectory 10 of the drone to the destination 22. This point may be badly positioned, in an unauthorized zone, or may even give rise to, to reach it, when the drone crosses prohibited areas, which in this case will cause a fall triggered via the on-board geocaging module 23 if present and a probable loss of the machine.

Thus, in one embodiment of the invention, the drone 2 is suitable for detecting a break in the telecommunications link 4 between the system 3 and the drone 2 and for upon detection of such a break, triggering a procedure for emergency landing at an emergency landing point (optionally in accordance with an emergency landing path) the coordinates of which are stored in a so-called emergency landing location of a memory of the piloting unit 21 .

In one embodiment of the invention, the preventive geocaging block 31 is adapted to automatically update via the link 4 an emergency landing location of the drone as a function of terrain data and / or obstacles of the second base, data from the base of authorized and / or prohibited flight zones, the geographic location of the drone indicated by current situation information and a maximum fixed deviation, in time or distance, of being joined by the drone of the emergency landing location.

For example, the preventive geocaging block 31 is adapted to search for an emergency landing point (and a diversion route to reach the most appropriate) while respecting the authorized and / or prohibited flight zones as defined by the database 36, by small portion of the nominal journey to be carried out by the drone 2 as a function of at least the piloting instructions transmitted to the drone by the system 3, for example every m minutes or k kilometers of journey, and for transmitting to the drone via the telecommunications interface 34, the coordinates of the most suitable emergency landing point for the section in progress. Thus, the coordinates of the emergency landing points 21a, 21b, 21c, 21st ... are successively defined and transmitted. These points, and optionally the associated diversion paths, are determined in one embodiment, taking further into account the nature of the terrain and the obstacles defined by the database 35 and / or the performance of the drone 2 and / or the current position of the drone, to aim for the best landing, and respecting the authorized flight zones and heights. Thus, drone 2 will always have, in the event of a link cut, a point (and optionally a diversion path) to apply defined as best as possible at the latest m minutes or k km (for example m = 3 and k = 3) . The drone 2 is suitable for, upon reception via the telecommunication interface 20, of the updated coordinates of the emergency landing point and optionally of the corresponding diversion path, to store it in the landing memory location d of the steering unit 21.

The regular updating of this emergency landing point during the flight makes it possible to secure the path of the drone and to perpetuate its use.

In an optional embodiment, an authentication device, for example by asymmetric keys (PKI) is added on the link 4 in order to guarantee that the drone 2 cannot be controlled from an RPS station which does not include preventive geocaging device.

With reference to FIG. 3, the steps of a method for remote control of a drone in an implementation mode of the invention implemented using the electronic remote control system 3 are now described .

In a step 101, the preventive geocaging block 31 receives the data regularly transmitted by the drone 2 comprising the current geographical location of the drone 2 determined by the geolocation block 22 and optionally the parameters defining the current situation of the drone determined by the optional device geocaging 23, wind information etc. The preventive geocaging block 31 also receives via the man-machine interface 30 piloting instructions established in accordance with the piloting mode of the drone 2 (mode 1, 2 or 3) as established by the remote pilot and that this the latter wishes to transmit to drone 2 via the telecommunications interface 34.

The preventive geocaging block 31, in a step 102, determines whether there is a risk of crossing (for example, potential crossing within 3 min of flight or 3 km away) or crossing of the authorized flight zone limit in function of :

- data from the database 36 of the authorized and / or prohibited zones and

- data received from the drone in step 101 and / or remote control instructions received in step 101.

The preventive geocaging block 31 also automatically updates the coordinates of the emergency landing point (and optionally a diversion path for each point) by path segment and transmits it to drone 2. Drone 2, upon receipt, stores this updated information of the emergency landing point and optionally of the corresponding diversion path, at the emergency landing memory location of the control unit 21. Thus subsequently, upon detection of a break in the link 4, drone 2 will head towards this point (following the diversion path, if memorized) defined best since at most m minutes or k km before.

In a step 103, if it has been determined in step 102 that there is a proven risk of crossing or a crossing by the drone 2, the preventive geocaging block 31 determines a piloting instruction intended for the drone to prevent the crossing of the flight zone limit which it transmits to the drone, possibly after validation by the remote pilot and / or blocks the transmission to the drone of a remote piloting instruction received to prevent the crossing of the flight zone limit which would have led to the implementation by the drone of such a remote control instruction as established in step 102.

The present invention thus makes it possible to secure the path of a drone 2 with respect to the no-fly zones.

Note that in the example described, the drone 2 is equipped with a geocaging device. However, the invention can be implemented vis-à-vis a drone not equipped with such a device.

In the embodiment described, three different control modes were considered. Obviously, a different number of control modes greater than or equal to 1 can be considered.

Claims (10)

1. - Electronic remote control system (3) for drones (2), comprising: - a first telecommunication interface (34) for establishing a telecommunication link (4) with a drone (2); - a second interface (30) for receiving remote control commands from the drone; - a first database (36) comprising data for defining the authorized flight area limit (s); a processing unit (33) adapted to transmit to the drone, via said first interface, remote control commands from the drone received via the second interface and adapted to receive, via the first interface, information on the current situation of the drone in origin of the drone indicating at least its geographic location; the remote control system (3) being characterized in that the processing unit is adapted to detect a risk of crossing the authorized flight zone limit as a function of data for definition of authorized flight zone limit (s) extracted from the first database and from at least one first element among current situation information received and a first remote control command received via the second interface and for, following said detection, performing at least one first operation among a set of operations including: the determination, as a function of said first control command and of an extrapolation over time of a control in accordance with said first command, of a situation of crossing of limit, and the triggering of an alarm as a function of said determination; - the determination of a second remote control command intended for the drone to prevent the crossing of the flight zone limit; - the blocking of the transmission to the drone of the first remote control command received via the second interface to prevent the crossing of the flight zone limit. 2. - Electronic remote control system (3) of drones according to claim 1, wherein the processing unit is adapted to automatically transmit the second command to the drone. 3. - Electronic remote control system (3) of drones according to claim 1 or 2, wherein the processing unit (33) is adapted to select a mode from among several operating modes, the determination of the second command of remote control comprising according to the selected mode at least the determination of one of the elements among the set of elements comprising the geographical coordinates of a future point of passage of the drone, an operating instruction of engines and / or of the control surfaces of the drone and a couple comprising a first heading or heading term and a second altitude or slope term, said element being selected from the set of elements according to the mode selected. 4. - electronic remote control system (3) for drones according to one of claims 1 to 3, in which the processing unit (33) is adapted to extract current situation information from the drone from the drone, a first geographic location of the drone from a first device for locating the drone and a second geographic location of the drone from a second device for locating a virtual security tool on board the drone, to compare the first and second locations geographic and to detect a deviation above a determined threshold between said compared geographic locations. 5. - Electronic remote control system (3) of drones according to one of the preceding claims, comprising a second database (35) of terrain and / or obstacles and in which the processing unit (33) is adapted to update an emergency landing location of the drone to be adopted by the drone on detection of break in the telecommunications link between the system and the drone as a function of terrain data and / or obstacles of the second base , data for defining the authorized flight area limit (s) of the first base, the geographic location of the drone indicated by current situation information and a maximum fixed deviation, in time or distance, of joining the emergency landing location, the processing unit (33) being adapted to transmit to the drone (2) via the first telecommunication interface (34) the updated emergency landing location. 6. - Method for remote control (3) of drones (2) implemented in an electronic system for remote control of drones, comprising the following steps: - establishment of a telecommunications link (4) with a drone (2); - reception of remote control commands from the drone; - reception, via the telecommunications link (4), of current situation information of the drone from the drone indicating at least its geographic location, the process being characterized in that it comprises the steps of: - detection of a risk of crossing the authorized flight zone limit as a function of authorized flight zone limit (s) definition data extracted from a first database (36) comprising limit definition data ( s) authorized flight area and at least one first element among current situation information received and a first remote control command received intended to be transmitted to the drone by the remote control system; and - following said detection, carrying out at least a first operation among a set of operations comprising: the determination, as a function of said first control command and of an extrapolation over time of control in accordance with said first command, of a situation of crossing of limit, and the triggering of an alarm as a function of said determination; o the determination of a second remote control command intended for the drone to prevent the crossing of the flight zone limit; o blocking the transmission to the drone of the first remote control command received via the second interface to prevent crossing of the flight zone limit. 7, - A method of remote control (3) of drones according to claim 6, comprising a step of selecting a mode from among several operating modes, the determination of the second remote control command comprising according to the selected mode at least the determination of one of the elements among the set of elements comprising the geographical coordinates of a future drone passage point, an operating instruction for the engines and / or the control surfaces of the drone and a torque comprising a first term of heading or route and a second altitude or slope term, said element being selected from the set of elements according to the mode selected. 8, - A method of remote control (3) of drones according to one of claims 6 to 7, comprising the steps of: - extraction of current situation information of the drone from the drone, a first geographic location of the drone from a first device for locating the drone and a second geographic location of the drone from a second device for locating a tool for virtual security on board the drone, - comparison of the first and second geographic locations and detection of a deviation greater than a determined threshold between said compared geographic locations. 5 9.- A method of remote control (3) of drones according to one of claims 6 to 8, comprising the steps of: - updating of an emergency landing location of the drone to be adopted by the drone on detection of break in the telecommunications link between the system and the drone according to terrain data and / or obstacles from a second database 10 (35) terrain and / or obstacles, data for defining the authorized flight area limit (s) of the first base, the geographic location of the drone indicated by current situation information and a deviation maximum fixed, in time or distance, to reach the emergency landing location and - transmission to the drone of the updated emergency landing location. 10.- Computer program comprising software instructions which, when executed by a computer, implement a method according to any one of claims 6 to 9.